Optical communications have become more prevalent as the demand for high-speed communication and processing has increased. Optical communications typically implement a laser for providing an optical signal, and at least one photodetector for converting the optical signal to an electric signal that can correspond to an intensity of the optical signal. As an example, a photodetector can be configured as a waveguide photodetector that can absorb photons associated with the optical signal propagating through a waveguide therein, such as via a material that has a high absorption coefficient, such that the waveguide photodetector can have a length dimension that facilitates greater absorption. As another example, a waveguide photodetector can be configured as an optical resonance cavity that is configured to resonate a specific wavelength and associated harmonics.